Immunogenetics & Transplantation

Question 1

Major histocompatibility complex or MHC is found on what chromosome?

Answer 1

The short arm of chromosome 6

Question 2

What does HLA stand for?

Answer 2

Human Leukocyte Antigen

Question 3

What are the three most important loci within the HLA?

Answer 3

HLA-A
HLA-B
HLA-D

Question 4

What do HLA-A and HLA-B code for?

Answer 4

Class I MCH- so they are going to be expressed on all nucleated cells + platelets

Question 5

What does HLA-D code for?

Answer 5

Class II MCH- So they are going to be expressed on macrophages, B cells, and dendritic cells

Question 6

How is HLA expressed?

Answer 6

Codominantly

Question 7

What is HLA-H associated with?

Answer 7

Codes for a protein that acts as a cofactor for duodenal crypt cells that increases the absorption of iron

Question 8

True or False: A positive one-way mixed leukocyte reaction would indicated that the donor is a good match for the recipiant.

Answer 8

False. It means that the recipients leukocytes are attaching the donors leukocytes

Question 9

Class I antigens are found on what cells?

Answer 9

All nucleated cells + platelets

Question 10

MHC Class II antigens are found on what cells?

Answer 10

B cells, marcrophages, dendritic cells

Question 11

Describe the MHC Class I structure.

Answer 11

Glycoproteins composed of two polypeptide chains

Allelicaly variable chain associated with invariant chain called beta2-microglobulin

Question 12

Describe the MHC Class II structure.

Answer 12

One alpha and one beta chain

Question 13

A female patient received a skin graft and over two weeks it became rejected. What can you probably say about the donor?

Answer 13

Male donor with the H-Y gene on the Y chromosome

Question 14

What is syngeneic or isografts?

Answer 14

Grafts between genetically identical individuals

Question 15

What is an allogenic or allograft?

Answer 15

Grafts between non-identical members of the same species

Question 16

What is a xenogeneic or xenograft?

Answer 16

Graft between members of different species

Question 17

What are autografts?

Answer 17

Grafts from one individual to themselves (hair transplants)

Question 18

True or False:

It’s almost never been possible to taper and stop a patient’s drugs without rejection

Answer 18

True

Question 19

What is hyperacute rejection?

Answer 19

It occurs when a graft is given to a patient who has preexisting antibody, IgG or IgM to it (If they had previous grafts or transfusions)

Question 20

Recognition of MCH I by CTL in transplant is usually not enough to activate them. What can increase the activation of the CTL cells?

Answer 20

If recipient Th1 cells are activated by recognition of donor MHC Class II. When they become activated they release INF-gamma which causes an inflammatory reaction and they also release IL-2 which activate CTL

Question 21

Is it more important to match MHC Class I or II?

Answer 21

MHC Class II because the Th1 cells will not become activated

Question 22

True or False:
The recognition of foreign MHC is a chance cross-reaction; the receptors are actually selected to reconize self-MHC + antigen

Answer 22

True

Question 23

HLA-B27 is associated with what disease?

Answer 23

Ankylosing spondylitis.

Calcification so that affected joints may become inflexible

Question 24

What disease is HLA-DR3 and -DR4 associated with?

Answer 24

Type 1 juvenile diabetes

Question 25

What does HLA-DR2 protect against?

Answer 25

Type 1 diabetes